In the conventional radio transceiver, an antenna is shared between a transmission path and a reception path, and a radio frequency (RF) signal is transmitted/received to/from the antenna. In such a radio transceiver, a filter for a transmission signal, an adjustment circuit such as a matching circuit, a filter for a reception signal, and an adjusting circuit such as a matching circuit are connected to the antenna (for example, refer to Patent Documents 1 to 3).
Therefore, at the time of transmission, it is necessary to switch the operation of the adjustment circuit for the transmission signal from off to on and to switch the operation of the adjustment circuit for the reception signal from on to off. Similarly, at the time of reception, it is necessary to switch the operation of the adjustment circuit for the reception signal from off to on and to switch the operation of the adjustment circuit for the transmission signal from on to off.
Therefore, the adjustment circuit for the transmission signal and the adjustment circuit for the reception signal each have a changeover switch for switching ON/OFF of operation and a control wiring for supplying a control signal for controlling the changeover switch.